Figure S1. Purification and characterization of budding yeast cohesin and its loader.

(A) Purification scheme for the cohesin tetramer complex. Size exclusion chromatography was the final purification step. Fractions from the column were analyzed by SDS–PAGE, followed by Coomassie Blue staining. Peak fractions corresponding to the cohesin tetramer complex were pooled and used for biochemical experiments described in this article. The cohesin tetramer complex contained a substoichiometric contamination from chaperones of the Hsp70 family (Ssa1-4, Ssb1-2, identified by mass spectrometry), indicated by “*”. The UV absorbance elution profile from the size exclusion column is also shown, together with the profiles of size markers used to calibrate the column. (B) As (A), but the purification scheme and final size exclusion chromatography step of the Scc2–Scc4 cohesin loader complex purification are shown.